1. Field of the Invention
The present invention relates to a honeycomb structure. More particularly, it relates to a honeycomb structure capable of suppressing cell deformation while realizing the lowering of a heat capacity and the decrease of a pressure loss.
2. Description of Related Art
In an exhaust gas discharged from an internal combustion engine such as an engine of a car, harmful substances such as carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx) are included. When these harmful substances are decreased to purify the exhaust gas, a catalyst reaction is broadly used. In this catalyst reaction, the generating of another harmless substance from a harmful substance such as carbon monoxide (CO) can be realized by simple means for bringing the exhaust gas into contact with a catalyst. Therefore, in the car or the like, the catalyst is usually disposed in the middle of an exhaust system, thereby performing the purification of the exhaust gas.
When the catalyst is disposed in the exhaust system of the car or the like, a honeycomb catalyst body onto which the catalyst is loaded onto a honeycomb structure is used. In the honeycomb catalyst body, a honeycomb configuration is formed by partition walls onto which the catalyst is loaded. Therefore, in the honeycomb catalyst body, a frequency of the contact between the exhaust gas and the catalyst is high, with the result that a high purification efficiency of the exhaust gas can be realized.
In recent years, concerning the honeycomb structure, the lowering of a heat capacity and the decrease of a pressure loss have further been required. To meet this requirement, the honeycomb structure in which a thickness of the partition walls is decreased to obtain a high open area ratio has been demanded. However, in the honeycomb structure of the high open area ratio, the problem occurs that a structural strength of the honeycomb structure weakens.
Thus, there has been suggested a high strength thin wall honeycomb structure in which a thickness of partition walls of an outer peripheral portion is regulated to heighten the structural strength while decreasing the thickness of the partition walls to realize a high open area ratio (an open area ratio of 80% or more) (Patent Document 1).
[Patent Document 1] JP-A-H11-277653